Laparoscopy dates back to the turn of the 20th Century. Early laparoscopic techniques were used primarily for diagnostic purposes to view the internal organs, without the necessity of conventional surgery. Since the 1930s, laparoscopy has been used for sterilization and, more recently, for suturing hernias. U.S. Pat. Nos. 4,919,152 and 4,944,443 are concerned with techniques for suturing hernias. Another recent innovation is the use of laparoscopic surgery for removing the gallbladder.
In the course of performing laparoscopic procedures in the abdomen, it is necessary to raise the abdominal wall to create space in which to work. A well-known method of raising the abdominal wall is to insufflate the abdominal cavity with a suitable insufflation gas, such as air, or carbon dioxide. A significant disadvantage of gas insufflation is that instruments must be passed into the abdominal cavity through gas-tight seals, which significantly reduce the surgeon's feel of the instruments.
Several mechanical alternatives to gas insufflation have been proposed. The Gazayerli Endoscopic Retractor Model 1, described in SURGICAL LAPAROSCOPY AND ENDOSCOPY, Vol. 1, No. 2, 1991, pages 98-100, has a rigid rod with a hinged blade at the distal end. The blade can rotate through 360 degrees about an axis perpendicular to the long axis of the rod. The blade is aligned with the long axis of the rod for insertion into the abdomen through a small puncture. Once inside the abdomen, the blade is swivelled through about 90 degrees to form a T-shaped structure. The proximal end of the rod can be raised by hand or by a rope, pulley and weight arrangement. Raising the rod causes the blade to engage the abdominal wall and to lift it.
French patent application no. 90-03980 shows a wire structure that is threaded into the abdomen through a small puncture to engage and to lift the abdominal wall. The application also shows a fan retractor that has a first angle-shaped member having a first leg that engages with the abdominal wall, a tubular second leg having a bore, and a third leg, remote from the first leg, that has a hook-shaped member on its end distal from the second leg. A second angle-shaped member has a first leg that engages with the abdominal wall, a second leg that pivots within the bore of the second leg of the first angle-shaped member, and a third leg, remote from the first leg, that serves as an operating lever for the second angle-shaped member. The first legs of the angle-shaped members are closed together to insert them into the abdominal cavity through an incision. The third leg of the second angle-shaped member is then operated to spread the first leg of the second angle-shaped member apart from the first leg of the first angle-shaped member. The first legs are engaged with the peritoneum inside the abdominal cavity. A lifting force is then applied to the hook-shaped member to lift the retractor and hence to lift the abdominal wall.
U.S. patent application Ser. No. 07/706,781, the application of which the parent of this application is a Continuation-in-Part, describes a number of different mechanical devices that are inserted through one or more punctures into the abdomen. All or part of the device is then lifted to lift the abdominal wall away from the underlying abdominal organs. One of the devices described in this application is a fan retractor that is inserted in a closed condition into the abdomen, spread apart once inside the abdomen, and brought into contact with the peritoneum inside the abdomen. The fan retractor is then raised by a lifting arm to lift the abdominal wall.
U.S. patent application Ser. No. 07/890,033, the application of which this application is a Continuation-in-Part, describes a fan retractor in which the second legs are adapted for insertion properitoneally, i.e., between the peritoneum and the properitoneal fat layer, by reducing their thickness and stiffness distally from the first legs. The peritoneum acts as a drape, and prevents the second legs from snagging and injuring the bowel or omentum. After the fan retractor has been placed between the peritoneum and the properitoneal fat layer, and its second legs have been spread apart, the fan retractor is raised by a lifting arm to lift the abdominal wall.
A single fan retractor raised by a lifting arm functions adequately in patients of normal body habitus and in mildly obese patients. It also functions adequately in procedures that involve manipulations and dissection of tissue and organs situated in the center of the abdomen. Inadequate visualization and working space occurs when a single fan retractor is used in obese and morbidly obese patients, and in procedures in normal patients where access to lateral regions of the abdomen, such as the paracolic gutters, is required.